OBJECTIVES: 1) Our quest to identify the recipient cell type of the geniculocortical projection will be continued. Current neuroanatomical methods, especially electron microscopy, will be employed to accomplish this objective. 2) We also plan to continue our study on the cell type in layer V, which is the recipient of the short axonal system that originates in overlying layer III of area 17. Again, current methods will be used on both the light and electron microscopic levels. BIBLIOGRAPHIC REFERENCES: J. Tigges, W.B. Spatz and M. Tigges: Efferent cortico-cortical fiber connections of area 18 in the squirrel monkey (Saimiri). J. Comp. Neurol. 158, 219-236 (1974). M. Tigges, J. Tigges and R.H. Lange: Tilt analysis of pleomorphic vesicles in the superficial layers of the superior colliculus of Galago and chimpanzee. J. Neurocytology 4, 289-300 (1975).